Fluid sampling



Nov. 23, 1965 v. GILL 3,218,868

FLUID SAMPLING Filed Aug. 8, 1962 INVENTOR BY WM #0f/m5 zwwjv/WCW A TTORNEYS.

United States Patent O 3,218,868 FLUID SAMPLING Vernon Gill, Tulsa, Okla., assignor to Sinclair Research, Inc., Wilmington, Del., a corporation of Delaware Filed Aug. 8, 1962, Ser. No. 215,695 4 Claims. (Cl. 73-422) This invention is a novel apparatus for trapping a liquid sample. The device is characterized by extraordinary simplicity, the device having but two moving parts, and by the provision it contains for trapping a live sample of the uid and releasing the sample to a storage vessel through the same duct used to introduce the sample into the trap. In this way the latest sample is obtained, rather than a sample obtained at the beginning or a previous portion of the ow period. Thus the device of this invention is designed for long and durable service and is of particular use in keeping informed of the composition, etc., of flowing liquid material which is subject to sudden variations in its characteristics.

The fluid sampling device of this invention has means whereby a fluid stream owing under pressure, passes directly through the sample chamber and whereby the release of fluid pressure causes discharge of a sample, trapped from the iiowing stream, to a storage or testing apparatus. Fluid is ejected to the storage or test apparatus through the same duct which admits it to the sample trap vand the ejection is preferably performed by the release of a spring which operates a piston. The movement of the piston in turn also controls the exit of the moving stream, from which the sample is taken, from the sample chamber.

The fluid sampling device of this invention is a hollow body, usually cylindrical in form and made of Teon, which provides a passage through which a iiuid stream passes and in which a uid sample is trapped. The passage has an inlet and outlet, usually on opposite ends of the'uid receiving portion, and thereby provides for liow of the sample completely through the chamber. The size of the chamber is determined by the piston which divides the hollow space within the body into a uid receiving chamber and a spring chamber.

Ideally, the uid sample trap of this invention will also have means associated with the inlet for adjusting the size of the sample chamber to the quantity of duid sample desired and for equalizinlg the iluid pressure on opposite sides of the piston.

The liquid sample trap may be fitted to any sort of pipeline or other system which carries uid under pressure. The connection to such a system preferably is by means of a multi-port valve arrangement which allows periodic communication between the pipeline and the inlet of the sample chamber. The fluid pressure in the pipeline serves to iiow fluid through the sample chamber and the cutting off of this pressure allows the spring to eject the trapped sample. The valve may be actuated, for example, by a timer, for continuous monitoring of the uid in the pipeline.

The invention will be better understood by reference to the accompanying drawings in which FIGURE 1 is a schematic view of an oil treatment and delivery system which uses the sampling device of this invention and FIGURE 2 is a cross-sectional view of the sampling device.

In the system of the drawings, means are provided for treating and storing a uid, Ifor example petroleum oil, and for delivering this fluid to further use while providing for periodic sampling of the uid in the delivery line for testing purposes. An oil composition, for example, oil containing connate water, -may be delivered to the lCe treating chamber 11 by the valved lines 13 or 15 and 17. Treated oil may be removed from the treater 11 by line 20 to surge tank 22 while separated water is removed by line 25. The line 27 which leads to the circulation pump 30, and valved line 33 leading from the pump to line 17, may be provided to keep the iluid in the surge tank circulating. Line 36 is provided for removal of fluid from the surge tank 22 to delivery by pump 39 and line 42.

The sampling system includes a three-port valve 44 connected to delivery line 42 by sample line 48. The valve 44 is also connected to sampling device 50 by line 53 and to sample container 55 by line 57. Valve 44 preferably is a solenoid-actuated valve connected to -a switching device 60, which preferably is a timer, by the electrical lead 63. Valve 44 may be a conventional type of twoposition solenoid actuated valve and it is so arranged in the system that line 53 is in communication with line 57 when the solenoid is energized and with line 48 when the solenoid is deenergized.

The sampling device comprises the generally hollow body 66 having an open end and a closed end with a longitudinal passage therein. A freely slidable piston 69 divides this passage into spring chamber 72 and sample chamber 75. As shown, the spring chamber 72 contains the coil spring 78. This spring and the piston 69 are the only parts of the sampling device which need move when in use. The body 66 is provided with the exhaust duct at about its midsection and near the end of the spring chamber 72, with the vent 82 which can lead to the outside of the body by holes 84 and/ or 86 and to the exhaust duct 80 by by-pass duct 88. As shown, ducts 84 and 86 may be yfully or partially plugged with screws and 93.

The open end of body 66 is provided with the sizing cylinder 96 which has the central entry and exit duct 99. As shown, this sizing cylinder may have the elongated neck portion 101 and may be fastened in position by one or more set-screws 103 in the washer 105. Washer 105 in turn is held to the body 66 -by two or more screws such as the screws 107 and the washer may be grooved as at 109 to hold a seal such as O-ring 111 which seals the space between body 66, washer and sizing cylinder 96. While described or alluded to as cylindrical, the central passage of body 66, as well as the piston 69 and the sizing cylinder 96 may be only partially circular or polygonal in form, so long as piston 69 and cylinder 96 tit snugly enough in the passage to prevent excessive leakage of uid around the piston or cylinder. Exhaust duct 80 may be joined by line 113 to circulation suction line 27.

The position of the moving elements in FIGURE 2 is illustrative of their position when the pump 39 is operating to deliver fluid and the switch 60 is open. The solenoid being deenergized, part of the uid being pumped by 39 is diverted to the line 48. This line communicates through the valve 44, with they line 53 and the duct 99. Pressure of fluid in the duct 99 is suiiicient to force the piston 69 to the right, in the drawing, against the bias `of the spring 78, creating the sample chamber 75. This fluid pressure continues to force the piston 69 to the right until the pressure is relieved by movement of the piston beyond the entry of duct 80. When this opening is suicient to stabilize the pressure in chamber 75, movement of the piston 69 ceases, but ow of the fluid continues through chamber 75, duct 80 and line 113.

When the switch 60 is closed, the solenoid of valve 44 is actuated, putting line 53 in communication with line 57 and ending How of fluid in line 48. The release of pressure from this liuid in chamber 75 allows spring 78 to push piston 69 back to the left in the drawing, covering the entry to duct 80 and forcing fluid from chamber 75 out through duct 99, line 53, valve 44 and line 57 to the sample container 5S. The compression force of spring 78 .is sutlicient to push piston 69 into close contact with cylinder 96, thus forcing a volume of uid equal to the volume of chamber 75 into the sample container. Vent 82 allows oil from by-pass 88 to relieve any vacuum formed in spring chamber 72. Y Also the bypass permits the use of a relatively loose-fitting piston 69 since oil leaked around the piston will not hamper its operation. This avoids having to equip piston 69 with seal rings with their accompanying expense. If a sealed piston is provided then the spring side of the piston could be vented to the atmosphere and by-pass 8S omitted, but this is not the preferred embodiment.

The freshness of the sample dictates a minimum length for lines 48, 53 and 57, if the latter is not vented. The timer may be set, for example, t energize the solenoid for fteen seconds each minute. The system preferably is provided with means for removing and replacing the sample container and instead of a sample container may be provided with continuous testing means, for example an electrolytic testing cell.

It is claimed:

1. A uid sample trap comprising a body having a passage therein, a uid inlet and a uid outlet spaced apart in said body and communicating with said passage, a piston slidably mounted in the passage dividing the passage into a fluid-receiving chamber and a spring chamber, said spring chamber being provided with a spring, biasing said piston towards said inlet and into a position of shut-off of said outlet with respect to said fluid-receiving chamber, said piston being slidably moved in the passage under the pressure of fluid from said inlet to enlarge said fluid-receiving chamber and compress the spring until said fluid-receiving chamber communicates with said Outlet, said piston being moved in the substantial absence of uid pressure from said inlet and due to the compression of thespring, to eject said fluid through said inlet, said inlet being housed in a means inserted in said body and being adjustable to determine the volume of said uid receiving chamber.

2. A uid sample trap of adjustable size comprising a body having a passage therein containing a piston slidably mounted in the passage dividing the passage into a fluidreceiving chamber and a spring chamber, said spring chamber being provided with a spring which is compressible by said piston and which biases said piston toward said Huid-receiving chamber, a movable inlet body adjustably held within said fluid-receiving chamber and providing a fluid inlet, a fluid outlet at the opposite end of said fluid-receiving chamber from said inlet body, and a vented by-pass duct connecting said outlet and said spring chamber, said piston being of a size suitable for being contained within said spring chamber and uncovering said outlet under the influence of lluid pressure in the said Huid-receiving chamber and of being contained within said fluid-receiving chamber and covering said fluid outlet under the influence of spring pressure.

3. A uid sampling lsystem adapted for continuously tal-:ing samples of pumped fluid of adjustable size from a line, comprising a uid sample trap, a sample container and a valve operable in one position to connect said line to a iluid receivingl chamber in said trap and in another position to connect said chamber to said container, said iluid sample trap comprising a body having a passage therein containing a piston slidably mounted in the passage dividing the passage into said fluid-receiving chamber and a spring chamber, said spring chamber being provided with a spring which is compressible by said piston and Which biases said piston toward said uid-receiving chamber, a movable inlet body adjustably held within said fluid-receiving chamber and providing a lluid inlet, a fluid outlet at the opposite end of said uid receiving chamber from said inlet body, and a vented by-pass duct connecting said outlet and said spring chamber, said piston being of a size suitable for being contained within said spring chamber and uncovering said outlet under the intluence of uid pressure in the said fluid-receiving chamber and of being contained within said fluid-receiving chamber to displace fluid to said container, and covering said fluid outlet under the influence of spring pressure.

4. The system of claim 3 in which the fluid outlet is in communication with a non-sampling portion of said pump fluid system.

References Cited by the Examiner UNITED STATES PATENTS 487,886 12/1892 Hausmann 73-429 1,454,765 5/1923 Patterson et al 222-444 X 2,196,681 4/1940 Moroney 73-421 2,260,419 10/1941 Wrightsman 73-422 RICHARD C. QUEISSER, Primary Examiner.

JOSEPH P. STRIZAK, Examiner. 

1. A FLUID SAMPLE TRAP COMPRISING A BODY HAVING A PASSAGE THEREIN, A FLUID INLET AND A FLUID OUTLET SPACED APART IN SAID BODY AND COMMUNICATING WITH SAID PASSAGE, A PISTON SLIDABLY MOUNTED IN THE PASSAGE DIVIDING THE PASSAGE INTO A FLUID-RECEIVING CHAMBER AND A SPRING CHAMBER, SAID SPRING CHAMBER BEING PROVIDED WITH A SPRING, BIASING SAID PISTON TOWARDS SAID INLET AND INTO A POSITION OF SHUT-OFF OF SAID OUTLET WITH RESPECT TO SAID FLUID-RECEIVING CHAMBER, SAID PISTON BEING SLIDABLY MOVED IN THE PASSAGE UNDER THE PRESSURE OF FLUID FROM SAID INLET TO 